The present invention relates generally to opening/closure arrangements for polymeric (plastic) packages and more particularly to a tear guide arrangement for opening a package from a sealed condition.
In many consumer packaging applications, it is important to prevent air or water or the like from passing out of or into a package containing certain food products. This is particularly true with respect to cheese packages, meat packages, and the like, for which the contained product must be kept in a constant environment to prevent spoilage. In order to preserve the product contained within such a package, the periphery of the package must be hermetically sealed. Hermetic seals can be provided by both permanent seals and temporary seals known as peelable seals. Peelable seals are capable of providing a hermetic seal and, at the same time, providing a consumer with access to the contents of a package. A consumer breaks a peelable seal of a package by first grabbing onto opposing film faces to which peelable seal materials are adhered and then pulling the film faces apart.
It is also desirable to provide a convenient and effective way to reseal the package after it has been opened. In this respect, reclosable zipper seals are advantageous. On the other hand, reclosable seals alone provide an opportunity for undesired tampering with the contents of a package. To reduce the opportunity for undetected tampering, packages with reclosable zippers can be permanently sealed above or below the reclosable zipper in such in manner that the opening of the package becomes apparent.
However, seals that inhibit tampering may be difficult for the consumer to open. Such seals may require the consumer to break the seals by cutting them with scissors or a knife. To overcome this problem, a perforated tear guide can be combined with a reclosable zipper to provide a package that is easy for the consumer to open and reseal while minimizing the opportunities for undetected presale product tampering.
In many product markets, it is common to use a thermoform packaging machine to package a product. The film for this type of packaging has a tacky sealant layer on its inner side. When two webs of film are brought together, the product and closure arrangement are sealed into the film. The film is also sealed to itself in one or more areas, thereby creating a peelable bond. The outer end of the closure arrangement is then perforated to allow for the end to be removed and to allow access to the zipper or seal. Existing tear guides and closure arrangements are inadequate because the film often gets tucked or sealed into the groove made by the perforation wheel. When this happens, it is difficult to grasp each side of the bag to open the locks of the zipper and ultimately to peel the seal to access the product.
A need therefore exists for a tear guide and closure arrangement for a polymeric package that overcomes the aforementioned shortcomings associated with existing tear guides and closure arrangements.
Accordingly, the invention described in this application is directed to a reclosable bag comprising convex and concave areas that interact to facilitate opening the bag. To initially open the bag, first and second films are separated from each other by tearing perforations. Next, interlocked closure profiles are detached from each other by grabbing onto gripper ridges and pulling the opening of the bag apart. If the first or second film becomes tucked into the groove left by the perforations such that the gripper ridges are difficult to access even after tearing the perforations, then the end of the opening may be flexed up or down, thereby causing the convex area and concave area to separate and provide access to the gripper ridges.